SARS-CoV-2 Omicron Detection by Antigen Tests Using Saliva

The Omicron is the predominant SARS-CoV-2 variant globally. It spreads more rapidly than ancestral lineages and its rapid detection is critical for the prevention of disease outbreaks. Antigen tests such as immunochromatographic assay (ICA) and chemiluminescent enzyme immunoassay (CLEIA) yield results more quickly than standard polymerase chain reaction (PCR). However, their utility for the detection of the Omicron remains unclear. We herein evaluated performance of ICA and CLEIA in 51 patients with Omicron and 60 negative individuals. Sensitivity and specificity of CLEIA yielded 100.0% (95%CI: 93.0–100.0%) and 100.0% (95%CI: 94.0–100.0%), respectively, with fine correlation with cycle threshold (Ct) value. Sensitivity and specificity of ICA was 58.8% (95%CI: 44.2-72.4%) and 100.0% (95%CI: 94.0–100.0%), respectively. Sensitivity of ICA was 100.0% (95%CI: 80.5-100.0%) for PCR Ct value less than 25. The Omicron can be efficiently detected in saliva by CLEIA. ICA also detects high viral load Omicron using saliva.

Note:
Funding Information: This study was supported by Japan Agency for Medical Research and Development (AMED) under Grant Number JP 20fk0108471.

Conflict of Interests: CLEIA test reagent (Lumipulse SARS-CoV-2 Ag kit), analyzer (LUMIPULSE G600) and ICA test kit were supplied by Fujirebio. IY reports grants from AMED during the conduct of the study; grants from KAKENHI, AMED, and Health, Labour and Welfare Policy Research Grants, research fund by Nihon Medi-Physics, and speaker fees from Chugai Pharmaceutical Co, AstraZeneca plt, Japan Tabacco Pharamaceutical Division, and Nippon Shinyaku Co, outside the submitted work. TT reports grant from AMED, during the conduct of the study; personal fees from Merck Sharp & Dohme, Takeda Pharmaceutical, Pfizer Japan, and Bristol Myers Squibb, grants and personal fees from Kyowa Hakko Kirin, grants, personal fees, and non-financial support from Novartis Pharma, grants from Chugai Pharmaceutical, Sanofi, Astellas Pharma, Teijin Pharma, Fuji Pharma, Nippon Shinyaku, the Japan Society for the Promotion of Science (Grants- in-Aid for Scientific Research), the Ministry of Health, Labour and Welfare, Japan(Health, Labour and Welfare Policy Research Grants), and the Center of Innovation Program of the Japan Science and Technology Agency, and non-financial support from Janssen Pharmaceutical, outside the submitted work. The other authors declare no conflict of interest.

Ethical Approval: This study was approved by the Institutional Ethics Board (Hokkaido University Hospital Division of Clinical Research SARS-CoV-2 Omicron detection by antigen tests using saliva Administration Number: 020-0116) and informed consent was obtained from all individuals orally to avoid spreading of the virus. This study was conducted in accordance with the Declaration of Helsinki and Ethical Guidelines for Medical and Biological Research Involving Human Subjects.

Keywords: SARS-CoV-2, COVID-19, Saliva, Lumipulse, ICA, CLEIA

Suggested Citation: Suggested Citation

Murakami, Kaoru and Iwasaki, Sumio and Oguri, Satoshi and Tanaka, Kumiko and Suzuki, Rigel and Hayasaka, Kasumi and Fujisawa, Shinichi and Watanabe, Chiaki and Konno, Satoshi and Yokota, Isao and Fukuhara, Takasuke and Murakami, Masaki and Teshima, Takanori, SARS-CoV-2 Omicron Detection by Antigen Tests Using Saliva. Available at SSRN: https://ssrn.com/abstract=4086698 or http://dx.doi.org/10.2139/ssrn.4086698